riskbycounty
FEMA NRI 1.19.0Updated Nov 2023 · Coverage 2014–2023Methodology

Boulder County Disaster Risk

Boulder County, Colorado

FEMA Risk Rating

Relatively Moderate

National Percentile

91th

of 3,144 counties

State Rank

#6

of 64 (1 = highest risk)

Flood Risk

92th

percentile

Hazard Risk Breakdown

Flood

River, coastal, and surface flooding risk

Moderate

Higher than 92% of US counties

Wildfire

Wildland and wildland-urban interface fire risk

Relatively High

Higher than 98% of US counties

Tornado

Tornado and severe thunderstorm risk

Moderate

Higher than 93% of US counties

Earthquake

Seismic activity and ground shaking risk

Relatively Low

Higher than 81% of US counties

Risk Overview

About Natural Disaster Risk in Boulder County, Colorado

Boulder County faces Colorado's highest disaster risk

Boulder County scores 90.71 on the composite risk scale, among the highest in the state and well above national averages, indicating relatively moderate but substantial multi-hazard exposure. This score reflects acute vulnerabilities across tornadoes, wildfire, flooding, and earthquakes.

Third-highest risk county in Colorado overall

Boulder's 90.71 composite score trails only Arapahoe (93.80) and Adams (91.19) in statewide disaster risk, facing more than double Colorado's average (40.67). The county's mountain-valley geography and population density concentrate multiple hazard vulnerabilities.

Boulder leads the Front Range in composite risk

Boulder (90.71) substantially exceeds Broomfield (34.70) to the east and ranks alongside Adams (91.19) and Arapahoe (93.80) as part of Colorado's highest-risk trio. This elevated exposure reflects the county's mountainous terrain and urban concentration.

Wildfire and floods define Boulder's hazard profile

Wildfire risk reaches 97.87—the highest in Colorado—reflecting extensive forests and terrain, while flood risk of 92.24 poses acute danger in canyons and drainages. Tornado exposure (92.59) and earthquake risk (80.50) add further complexity to this multi-peril environment.

Comprehensive multi-peril insurance is essential

Boulder residents must carry flood insurance (92.24 risk) and maintain wildfire defensibility with adequate coverage, as standard policies exclude both hazards. Earthquake insurance should also be considered given the 80.50 risk score, making layered protection critical in this high-risk county.

Source: FEMA National Risk Index · Narrative reviewed by Evan Brooks, Data Editor

Preparedness Guide

What to Prepare for in Boulder County

Top Hazards by Exposure

  1. #1
    WildfirePrepare
    98th percentile
  2. #2
    TornadoPrepare
    93th percentile
  3. #3
    FloodPrepare
    92th percentile

Source: FEMA National Risk Index v1.19.0 · Percentiles are national (3,144 counties)

Local Resources

Risk Advisory: Boulder County

Risk Verdict

Boulder County registers a moderately elevated natural disaster risk, ranking at the 91th percentile across all U.S. counties. High composite risk signals that multiple hazard types are elevated simultaneously; planning for more than one scenario is important in Boulder County.

Hazard Breakdown

Wildfire risk is Boulder County's dominant natural hazard, ranked at the 98th percentile nationally under FEMA's National Risk Index. Tornado ranks second at the 93th percentile nationally. Additional tracked hazards include flood (92th percentile), earthquake (81th percentile).

Preparedness Context

Wildfire ranks as Boulder County's primary hazard at the 98th percentile nationally. For Boulder County households in high-WUI areas, go-bag readiness — the ability to leave within 15 minutes — is more important than shelter-in-place planning for most residential properties. Alongside wildfire, tornado at the 93th percentile nationally means a multi-season preparedness mindset — fire season and flood or storm season often require different household plans. Boulder County county's local emergency management office publishes community-specific wildfire risk assessments and evacuation zone maps; households should review their zone assignment and sign up for zone-specific alerts.

Regional Context

Boulder County falls 50.0 points above Colorado's typical county risk level, which means the hazard environment here is notably more demanding than the state baseline.

Is your household prepared for Boulder County's hazards?

Review FEMA's county-specific preparedness checklists and emergency planning guides.

FEMA Ready Guide →

Frequently Asked Questions

What is the natural disaster risk in Boulder County, CO?
Boulder County has a FEMA National Risk Index rating of Relatively Moderate, placing it in the 91th percentile nationally out of 3,144 counties. This composite score reflects the county's overall exposure to natural hazards including floods, wildfires, tornadoes, earthquakes, and hurricanes, weighted by expected annual loss and social vulnerability.
What types of natural hazards affect Boulder County?
Boulder County is evaluated for five major natural hazard types: wildfire (98th percentile), tornado (93th percentile), flooding (92th percentile), earthquake (81th percentile). The highest-risk hazard is wildfire at the 98th percentile nationally. These scores are derived from FEMA's National Risk Index, which analyzes expected annual loss, social vulnerability, and community resilience for each hazard type.
How does Boulder County risk compare to the Colorado average?
Boulder County's composite risk percentile is 91th, compared to the Colorado state average of 41th percentile. The state's overall risk rating is Very Low. This means Boulder County faces higher natural disaster risk than the typical county in Colorado.
Is Boulder County at risk for wildfire?
Yes, Boulder County's wildfire risk is at the 98th percentile nationally. This places it in the top quartile for this hazard type. For flooding specifically, Boulder County is at the 92th percentile.
How is natural disaster risk measured?
FEMA's National Risk Index (NRI) calculates risk scores for 18 natural hazard types across all U.S. counties and census tracts. The composite score combines Expected Annual Loss (estimated dollar losses from each hazard), Social Vulnerability (demographic factors affecting disaster impact), and Community Resilience (ability to recover). Percentile scores rank each county against all 3,144 U.S. counties, and risk ratings range from Very Low to Very High.
Why is Boulder County higher risk than average?
Boulder County's composite risk score of 91th percentile is above the Colorado state average of 41th percentile. This elevated risk is driven by wildfire exposure (98th percentile), along with tornado and flooding and earthquake risk. Geographic location, terrain, climate patterns, and proximity to flood zones or fault lines all influence a county's risk profile.

Counties with Similar Risk

Adams County

Colorado

+0.5

Relatively Moderate

91th percentile

Larimer County

Colorado

-0.6

Relatively Moderate

90th percentile

Weld County

Colorado

-1.6

Relatively Moderate

89th percentile

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Data Source

Risk data sourced from the FEMA National Risk Index (NRI). Risk scores are relative rankings (0–100) across all US counties — not absolute risk measures. Higher scores indicate higher relative risk compared to other counties.

Disclaimer: This data is informational only. It is not financial, insurance, or legal advice. Always consult a qualified professional before making insurance or real estate decisions.

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